Two problems related to brake master cylinder have been reported for the 1999 Ford F-350. The most recently reported issues are listed below.
While driving 45-65 mph, brakes malfunction/ lock up, consumer took vehicle to dealer twice. Consumer states that on 23-Feb-2002 dealer replaced hydro boost and front pads vehicle started locking up again, on 24-Feb-2002 dealer replaced master cylinder and now brakes are working.
There is a problem with braking on the diesel trucks. When appling the brakes in a panic situation and one or both of the rear wheels loose traction, the rabs kicks in and the pedal goes to the floor. This is also accompanied by sudden increase in steering effort at the same time if an attempt is made to steer around an accident situation. These diesel trucks use a hydro boost system run off of the power steering pump for the brakes. There is also a sudden decrease, many times severe, in braking power. When this happens, the only way to regain the brakes is to release them and reapply them, taking great care not to skid one or both of the rear tires. Talking to other owners, it appears to be a design flaw and replacing parts will not repair the situation. The master cylinder and calipers are all working properly and this truck has done it from the day it was new. There have been several instances where I have had to apply the brakes in a panic stop and had one or both of the rear wheels start to skid. The brake pedal then goes to the floor, braking is severely diminished and the ability to stop is virtually non-existent. Only by releasing and re-applying the brakes can braking be restored and it is only through this effort and the experience of years of driving police vehicles that I have been able to avoid several accidents. Dt.